The easy answer to this is buy a central locking kit
If you want to biuld this you will need to have the following pre requisits
Understanding of solonoids and motor theory
Understanding of micro controllers
Understanding of embedded programming langauges
Understanding of sensors
Understanding of current sensing
Understanding of semiconductors
Would be conversant with pcb design,assembly and test
Component recognision
If you want to move along the can bus route
You would also need to understand this protocol with error handling and also be able to write software for such archtecture
Finally if you wanted remote control you would also need understanding and application of infra red, rf, and rolling code techniques. Plus circuitry
Last but not least this type of technology even for cars, as simple as this may seem, is moving towards fibre optic commnunication subsytems for message handling between modules and can bus controllers
Looks easy doesent it but thats the extent of knowledge you now need to have in order to design and build this Not impossible but never the less unless you have been doing some of this for quite some time
Its not easy but it can be done if you have knowledge of the above In fact I should also include within this pwm which is used to drive actuators as well in some designs
